Weird Bashing Quirk

I've been bashing and I'm seeing something that is kind of annoying and I'm wondering what exactly the deal is? Basically this has been happening on a specific denizen I hunt a lot, and it's every single time now that I've noticed it.

This is an imperfect comparison as it starts rounding one stage early compared to what you listed, but you get the idea.

As far as I know NPCs do not regenerate health at all until they go to sleep, unless they have a life-drain attack. Some boss-type NPCs or other special cases may behave differently. If the NPC had a life-drain attack you would know it because that shit is op af.

From what I have seen, if the target isn't in the room on their next balance, they will tend to their wounds if they are above shielding %, otherwise they will shield and start tending when they get the next balance after that.